Electric-circuit control.



H. J. MURRAY.

ELECTRIC CIRCUIT CONTROL.

APPLICATION FILED MAY I2, I917.

1 ,288, 1 28. Patented Dec. 17, 1918.

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HOWARD J. MURRAY, OF BROOKLYN, NEW YORK.

ELECTRIC-CIRCUIT CONTROL.

Specificationof Letters Patent.

Patented Dec. 17, 1918.

Application filed May 12, 1917. Serial No. 188,277.

To all whom it may concern:

Be it known that I, HOWARD J. MURRAY,

a citizen of the United States, and resident such a circuit closure constituting gart of an automatically actuated signaling evice for use on motor cars to indicate change in rate of travel.

In such devices now known, the opening or closing of the circuit is efiected solely by the inertia forces which are due to changes in the movement of the body to which the device is attached. Such devices are obviously defective in that the duration of contact does not include the entire time of acceleration or deceleration and this defect is especially noticeable in a'signaling device which with known types of circuit changing mechanism set up a quivering action, under those conditionswhere the deceleration or acceleration is not uniform.

Accordingly, one of the objects of my invention is to provide a simple means for changing the electric condition of a circuit, so as to control electrically operated mechanisms automatically from a change in velocity of moving parts carrying the contacts but which means is so arranged that it is possible to overlap the change of motion of the body to which the device is attached and thus steady the action of the signaling device.

This object is attained broadly by providing a relatively fixed and amovable contactmounted so that the closing of'the contact by the inertia of the movable contact will bring into existence a second force deslgned Y to lightly hold the contact and to so regulate the engagement that the contact is effected only when a material change has occurred in the inertia factor controlling the movable contact. One means for effecting this result is to cause the movable contact to come under the influence of an electro-magnet so arranged that the magnet will either attract or repel the movable contact, as desired, when acting under the force of its own inertia.

Various other objects and advantages of the invention will be in part obvious from an inspection of the accompanying drawings and in part will be more fully set forth in the following particular description of one form of mechanism embodying my invention, and the invention also consists in .cer-

tain new and novel features of construction and combination of parts hereinafter set forth and claimed.

In the drawings:

Figure l is a vertical sectional view through a preferred embodiment of my invention; and

Fig. 2 is a diagrammatic view of the parts together with their electric connections.

In the following description and in the claims, parts will be identified by specific names for convenience of expression but they are intended to be as generic in their application to similar parts as the art will permit.

In the drawings the parts are shown to be housed Within a casing 3 designed to contain all of the parts with the possible exception of the source of electric power and the manual controlled switches which may be used. This device is particularly designed to be mounted at the rear of an automobile for the purpose of indicating a change in speed conditions of the vehicle. A relatively stationary contact l is fixedly mounted within the casing 3 and is preferably in the formof a set-screw threaded into a support 5, so that the engaging end of the contact may be adjusted relative to the support and a nutlock 6 may be used to lock the same in set position. movable electric contact 9 coacts with contact 4: to complete the circuit and actuate any device controlled thereby. The second contact is mounted for free movement toward its coacting contact in the direction paralleling the direction of travel of the vehicle as indicated by the arrow in Fig. 1.

In some of the uses to which this device may be placed, it is desired to hold the contact in an inoperative position spaced from .the fixed contact or it may be desired to maintain the contact normally in circuit closing position, in either of which cases a contacts to or away from its coacting find contact. The spring may be regarded either as a compression spring or a tension spring, depending upon the desired contact or noncontactual relation of the contacts.

pendulum 12, fulcrumed at a fixed support 13 and Wei hted by means of a Weight 14 slidably ad usted along the length of the pendulum.

The device is operatively connected to a source of energy lfi herein indicated dia-' grammatically by parallel power lines, one of which is connected by a conductor L6 to a signaling device 17 herein shown to be an electric light lamp positioned within a reflector shell 18 constituting part of the me matter of my co-pending application, Serial No. 12,100, filed Mar. 4, 1915.

In this construction the pendulum is also provided with an armature 22 operatively disposed relative to the core 23 of an electromagnet 24 carried within the casing 3, so that the closing of the circuit through the contacts 4 and 9 will energize the electromagnet and cause its core to attract the armature 22. The closing of the contacts 4 and 9 will energize the signaling device through the conductor 25, which leads from one side of the switch 21 to the pendulum and through a conductor 26 which-leads from the contact 4 .to the conductor 19. One side of the electromagnet is connected with the conductor 26 by means of a conductor 27 and the otherside of the electro-magnet is connected to the conductor 16 by means of 'a conductor 28 which contains in its circuit a variable resistance 29.

In operation, and assuming that the device is mounted upon a traveling vehicle and is suitably connected with its source of elec tric power and with the switch 21 closed and switch 20 opened, it will be evident that during the time While the vehicle is decreasing its rate of motion in the direction indicated by the arrow in Fig. 1, the weight 14 will acquire motion in the direction indicated by the arrow, due to its inertia,-which will tend -t0 keep it moving at its original rate of motion. This motion will move the contact 9 into electric engagement with the contact 4 which will complete the circuit through the.

The moving contact is shown mounted upon a electro-magnet and its core will attract the armature 22 attached to the pendulum. At

lum armature is equal to the force of gravity tending to restore the weight 14 to its normal position, whenboth the casing and the weight 14 have no motion. This is also the condition when the motion of the casing or body to which it is attached and the weight 14 have acquired uniform constant motion, that is, when there is neither acceleration nor deceleration of the casing and its attached parts. If; under these conditions, the easing and its attached parts, decrease its rate of deceleration, and due to the relative motion between the casing and the weight 14, the force tending to hold armature 21 against the core 22 decreases, and ifthe deceleration is sufficient, the weight 14 will open-the circuit and aifect the signal'such as to permit it to return to its normal position, even if the deceleration has not entirely ceased. i

Should the pull of'the magnet be equal to the force of gravity acting on the pendulum, or perha s slightly less, then the contacts 4 and 9 will be held together until'deceleration has entirely ceased. Inv other words, the signal will continue to operate until deceleration or acceleration has entirely ceased or the body has acquired approximately uniform constant motion.

By varying the resistance any desired holding efi'ect may be produced even to the extent of continually holding the contacts 4 and 9 in electric engagement.

While I have shown and described, and have pointed out in the annexed claims, certain novel features of my invention, it will 'be understood that various omissions, substitutions and changes in the form and details of the device illustrated and in its oper-, ation may be made by those skilled in the art without departing from the spirit of the invention.

Having thus described my invention, 1 claim:

=1. Ina device of the class described, the combination with a relatively fixed contact, a second contact movable under the force of its inertia into position to affect its circuit closing relation with said fixed contact, means acting on the movable contact for affecting its circuit closing relation with the fixed contact, and meansfor moving said movable contact quickly" into its inoperative position.

2. In a device oflthe class described, the combination with a relatively fixed contact, a second contact movable under the force of its inertia intoposition to affect its circuit closing relation with said fixed contact and electro-magfietically actuated means governed by the relation of said contacts and acting on the movable contact for affecting its circuit closing relation with the fixed contact.

3. A circuit closer including a relatively fixed contact and a movable contact coacting with said fixed contact to make an electric engagement therewith, a plurality of power means for affecting said engagement, one of said means being actuated by the inertia of said movable contact and the other power means being operatively responsive to the movement of said movable contact and acting to hold the movable contact in a preset fixed position.

4. In a device of the class described, the combination with a relatively fixed contact, a second contact movable underthe force of its inertia into position to afiect its circuit closing relation with said fixed contact and locking means for holding the movable contact in circuit closing position.

5. In a device of the class described, the

\ combination with a relatively fixed contact,

a second contact movable under the force of its inertia into positionto affect its circuit closing relation with said fixed contact, means for holdin the movable contact in circuit closing position and means acting on the movable contact tending normally to move the same into an inoperative position. 6. In a device of the class described, the combination with a relatively fixed contact, a second contact movable'under the force of its inertia into position to affect its circuit closing relation with said fixed contact, means for holdin circuit closing position and adjustable means acting on the movable contact tending normally to move the same into an inoperative position.

7. In a device of the class described, the

combination of a relatively fixed contact, a second contact movable under the force of its inertia into position to affect the electrical relation of said contacts and means for holding said contacts in a preset relation, said movable contact being freely mounted so as to be prom tly responsive to inertia forces imposed t ereon. t

8. In a device of the class described, the

the movable contact in combination of a relatively fixed contact, a second contact movable under the force of its inertia into position to affect the electrical relation of said contacts, means for holding said'contacts in a set relation and means for varying the holding eifect of said contact-holding means.

9. In a device of the class described, the combination of a pendulum, a contact and an armature carried by said pendulum, an electromagnet coacting with said armature to efiect a movement of the pendulum, a second contact coacting with the contact on the pendulum to close the circuit through the electro-magnet.

10. In a device of the class described, the combination of a pendulum, a contact and an armature carried by said pendulum, an electromagnet coacting with said armature to efiect a movement of the pendulum, a second contact coacting with the contact on the pendulum to close the circuit through the electromagnet, and a rheostat for varying the electromagnetic action of the electromagnet on the pendulum armature.

11. In a device of the class described, the combination of a pendulum, a contact and an armature carried by said pendulum, an electromagnet coacting with said armature to efiect a movement of-the pendulum, a second contact coacting with the contact on the pendulum to close the circuit through the electro-magnet and an electric device actuated by the closing of the circuit through said contacts.

12. In a device of the class described, the combination of a pendulum, a contact and an armature carried by said pendulum, an electromagnet coacting with said armature to effect a movement of the pendulum, a second contact coacting with the contact on the pendulum to close the circuit through the electro-magnet, an electric device actuated by the closing of the circuit through said contacts and 'a manually actuated switch for closing the circuit through said electric device independently of the closing of the circuit by said contacts.

Signed at New York city this 3rd day of May, A. D., 1917.

HOWARD J. MURRAY.

Witness: v

H. S. Rrcnuono. 

